Some Percentages Are Just Fair-Weather Friends

By

Carl Bialik

Updated Jan. 25, 2013 8:02 p.m. ET

Winter weather advisory: Two of the most common graphical representations of percentages in daily life could behave differently in the cold.

Those icons showing how much battery life is left on your smartphone, already an imperfect gauge at room temperature, can be even less precise in the frozen outdoors. And the little sun or rain-cloud symbols on weather websites, which are hardly a sure guide to precipitation during the warmer months, are getting a tweak from the Weather Channel that could make them more accurate in...